1. Technical Field
The present invention relates to a tube unit, a control unit, and a micropump configured with them mounted thereon.
2. Related Art
As an apparatus which transports a liquid at a low speed, there is a peristaltic drive type pump. As the peristaltic drive type pump, a structure is known in which a rotor including a plurality of rollers is rotated with a step motor as a drive source, and the rotor rotates along a soft tube while causing the plurality of rollers to roll, carrying out a suction and discharge of a liquid (for example, Japanese Patent No. 3,177,742).
This kind of pump has a configuration wherein a pump module including a tube and a rotor pressing and closing the tube, and a motor module including a step motor and an output gear mechanism, are assembled stacked one on the other, a gear acting as a coupling element is provided on the rotating shaft of the rotor, a pinion acting as a power extraction mechanism is provided on the output gear mechanism and, when the pump module and motor module are connected stacked one on the other, by causing the pinion and gear to mesh with each other, a rotary drive force of the step motor is transmitted to the rotor.
This kind of peristaltic drive type pump of Japanese Patent No. 3,177,742 has a problem in that, as the tube is always pressed and closed by the roller after the pump has been manufactured, in the event that there is a long period from the pump being manufactured (assembled) until it is used, the tube deteriorates, and a liquid discharge accuracy cannot be secured.
Also, it is conceivable that, when the pump module and motor module are mounted stacked one on the other, as the structure causes the pinion and gear to mesh with each other, in the event that their teeth are out of phase with each other, the pinion and gear overlap each other, and are broken.